The proposed animal studies are directed toward quantitation of endothelial binding sites within the pulmonary circulation. A technique for use of 106Ru-labelled ruthenium red as a surface marker will be developed. The binding sites for circulating amines will be related to the volume of distribution of 106Ru-red ("ruthenium space"). In addition, variables affecting palmitic acid utilization by the lung will be defined by a) modifying the cation (Na, K) content of incubating media and b) utilizing DL-2-bromopalmitate, a non-metabolizable analogue of palmitic acid. Finally, the biochemical defect of alcohol-induced suppression of palmitic acid utilization will be identified by measuring the calcium and alpha-glycerophosphate content in lungs of alcohol-fed rats. The contemplated clinical studies will expand information on the interrelation between extracellular bicarbonate and the chemoregulation of respiration and establish a relationship between cardiac output and ventilation, independent of oxygen consumption or exercise.